1. Field of the Disclosure
The present disclosure relates to a protection relay, and particularly, to an event communication apparatus for a protection relay.
2. Background of the Disclosure
Protection relays are relays that have a function of measuring amounts of voltage, current, and power of an electric power distribution line and a function of detecting a fault state of a protection target, in addition to a basic relay function. Among such protection relays, a protection relay having a remote communication function is connected to an supervisory monitor through a communication line, and periodically transmits information (in other words data) of the protection relay to the supervisory monitor according to an industrial communication protocol.
In other words, when event information such as a measurement value of amounts of voltage, current, and electric power, status information such as a fault status, an external contact status signal input, a contact control output based on a predetermined sequence, or information about an operation of a protection target is updated, the protection relay having the remote communication function may form a response communication frame to transmit the response communication frame in response to a periodic transmission request of the supervisory monitor.
Moreover, in communication using an industrial communication protocol having a data anti-collision function, event information may be automatically transmitted to the supervisory monitor even without a transmission request of the supervisory monitor.
A configuration of an event communication apparatus for a protection relay of the related art will be described with reference to FIGS. 1 to 3.
First, a configuration of a related art protection relay will now be described with reference to FIG. 1 that is a block diagram illustrating the configuration of the related art protection relay.
A related art protection relay 100 includes an converting module 30, a communication module 20, a digital input/output module 40, an interface module 50, and a main processing module 10.
The converting module 30 is a module that senses a voltage and current of a relay line, and converts an amount of electricity into data.
The communication module 20 is a module that communicates with an supervisory monitor.
The digital input/output module 40 is a module that receives a contact status signal to output a digital output signal to an external device such as circuit breaker.
The interface module 50 is a screen display module that externally displays a sensing value of the voltage and current of the relay line, which is supplied from the converting module 30, or information about a contact status.
The main processing module 10 is a module that is connected to the converting module 30, the communication module 20, the digital input/output module 40, and the interface module 50, collects data from the modules 30, 20, 40, 50, and controls an operation of the modules.
The main processing module 10 and the other modules are connected to each other through a bus, and exchange information through communication.
A configuration and operation of a related art event communication apparatus in the protection relay 100 will be described with reference to FIGS. 2 and 3.
Referring to FIG. 2, the related art event communication apparatus in the protection relay 100 includes a main processing module 10, a shared memory 60, and a communication module 20.
The related art event communication apparatus further includes the shared memory 60, in addition to the above-described main processing module 10 and communication module 20.
The shared memory 60 is a memory that is shared by the main processing module 10 and the communication module 20. The shared memory 60 is used for that the communication module 20 requests event data by using the shared memory 60, the main processing module 10 writes the event data into the shared memory 60 in response to the request, and the communication module 20 again reads out the event data from the shared memory 60 to transmit the read event data to the supervisory monitor 200 to report to the supervisory monitor 200.
As seen in FIG. 3, at the step S1, the communication module 20 writes an event data-requesting message into the shared memory 60 to request event data to the main processing module 10.
Then, the main processing module reads out the event data-requesting message from the shared memory 60, and writes event data into the shared memory 60 to respond to the event data request (step S2).
And then, the communication module 20 reads out the event data from the shared memory 60, and determines event data by leaving event data needed to report to the supervisory monitor 200 (step S3).
Subsequently, at the step S4, the communication module 20 determines whether the event data is the event data needed to report to the supervisory monitor 200 or not.
When it is determined that the event data is the event data needed to report to the supervisory monitor 200, an operation proceeds to the step S5. On the other hand, when it is determined that the event data is needless event data instead of the event data needed to report to the supervisory monitor 200, an operation returns to the step S1.
Subsequently, at the step S5, the communication module 20 stores the event data, needed to report to the supervisory monitor 200, in an upper stream transmission event buffer (not shown) included in the communication module 20.
Subsequently, at the step S6, the communication module 20 transmits the event data from the upper stream transmission event buffer to the supervisory monitor 200.
As a result, the operation of the related art event communication apparatus is ended.
In the related art event communication apparatus, a time taken until the main processing module 10 writes event data into the shared memory 60 in response to an event data request of the communication module 20 may be delayed. In particular, as the number of event data increases, a time taken until the main processing module 10 writes all the event data into the shared memory 60 may be delayed. Since the main processing module 10 should communicate with the interface module 50 and the converting module 30 in addition to a corresponding response, time delay occurs in responding to event data requested by the communication module 20 according to a work priority of the main processing module 10.
In terms of the communication module 20, when low-priority communication with the supervisory monitor 200 and high-priority determination (the above-described the step S3) of an event are performed at the same time, the low-priority communication with the supervisory monitor 200 is delayed until a high-priority operation of determining the event is ended, and for this reason, a data communication speed between the communication module 20 and the supervisory monitor 200 can be slower. On the other hand, when a priority of an event determination operation by the main processing module 10 and the communication module 20 is lower than that of communication with the supervisory monitor 200, the data communication speed between the communication module 20 and the supervisory monitor 200 can be satisfied, but an updating of event data can be worse.
Therefore, a method for effectively simplifying an event determination operation by the main processing module 10 and the communication module 20 is needed.